Automatic apparatus for packaging powdered material with uniform bag weight and with dust-free operation

ABSTRACT

An automatic packaging apparatus for powdered material in which such material is fluidized in an air chamber and delivered by air to a filling means associated with a receiving bag. Flow control means are provided responsive to automatic weighing means, and recirculation means are provided for returning the dust from the air chamber and the region of the filling means for recirculation.

United States Patent Inventor Appl. No. Filed Patented Assignee AUTOMATIC APPARATUS FOR PACKAGING POWDERED MATERIAL WITH UNIFORM BAG WEIGHT AND WITH DUST-FREE OPERATION Primary Examiner-Charles J Myhre Attorney-Oberlin, Maky, Donnelly and Renner 9 Claims 10 Drawing Figs ABSTRACT: An automatic packaging apparatus for pow- U.S.Cl. 141/59, dered material in which such material is fluidized in an air 141/68, 141/ 128, 141/317 chamber and delivered by air to a filling means associated with Int. Cl l. B65b l/ 18, a receiving bag. Flow control means are provided responsive B65b1/34 to automatic weighingmeans, and recirculation means are Field of Search 141/67, 68, provided for returning the dust from the air chamber and the 59, 128, 317 region of the filling means for recirculation.

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' SHEEIlUF3 'FIG.1 mini F IINVENTOR PATENIFQD m1 1 l97l SHEET 2 [BF 3 INVENTOR km umw BY I ATTORNEY PATENTED mu 1 m SHEET 3 0r 3 a min WI 11.. L M 8 M4 m m 5 5 I a w INVENTOR ATTORNEY AUTOMATIC APPARATUS FOR PACKAGING POWDERED MATERIAL WITH UNIFORM BAG WEIGHT 'AND WITH DUST-FREE OPERATION BACKGROUND OF THE INVENTION This invention relates to an automatic apparatus for packaging powdered materials such as carbon black, starch, wheat flour, fly ash, powdered synthetic resin, diatomaceous earth, fertilizer and other chemical by-products, with uniform bag weight and with dust-free operation, while in a fluidized state of the materials.

According to the packer heretofore used, an uniformity of the bag weight is not obtained due to the difiiculties in, the fine bag discharge of the material to be packaged.

Further, the air impervious bags such as polyethylene, polyvinyl, vinyl bags or laminated paper bags, for example, are used to prevent the packaged material from being moistened. According to the conventional apparatus of this class, however, the quick filling of the material into such air impervious bags cannot be achieved since the material escapes outside through the clearance formed between the discharge spout and the inlet of the bag.

SUMMARY OF THE INVENTION .It is, therefore, a principal object of .the invention to eliminate the above difficulties and disadvantages and to provide a new automatic apparatus for packaging powdered material with accurate and uniform bag weight and with dustfree operation, which enables the accomplishment of such packaging even for the air impervious bag with a high filling speed. I

Another object of the invention is to provide an automatic apparatus for packaging powdered material with uniform bag weight in which means for filling the material is provided with a flow control system which comprises two feed pipes having different diameters, i.e. one for the full flow and the other for dribble flow so that the flow rate of the material at the final step of the packaging is finely controlled.

Still another object of the invention is to provide an automatic apparatus for packaging powdered material with uniform bag weight in which an open end of the feed pipe of smaller diameter for dribble flow of the material is covered with a grid screen to prevent the said feed pipe from being plugged.

Yet another object of the invention is to provide an automatic apparatus for packaging powdered material with uniform bag weight in which means for filling the material at its open end is provided with a mesh means so that the air discharged into the bag together with powdered material may be exhausted through an exhaust pipe connected to the said filling means of the material.

A further object of the invention is to provide an automatic apparatus for packaging powdered material with uniform bag weight in which an outer periphery of the filling means at its base portion is provided with a retractable valve means into which an air supply pipe is connected so that the clearance formed between the filling means and the inlet of the bag may be sealed airtightly when the said valve means is expanded by the air supply. 7

Still a further object of the invention is to provide an automatic apparatus for packaging powdered material with uniform bag weight in which a weighing system comprises a main balance weight means and an auxiliary balanceweight means which are cooperative with the flow control means consisting of two feed pipes of different diameters to ensure a highly accurate weighing.

And a further important object of the invention is to provide an automatic apparatus for packaging powdered material with dust-free operation and a high filling speed in which air exhaust means are connected to the aerator units arranged at the lower inclined periphery of the air chamber and at the bottom of the housing, and to the filling means and are assembled into the dust collecting means which communicates with the upper serge bin so that all the leaked dusts are perfectly fed back by thecirculation system.

These and other objects and advantages of this invention will become readily apparent and be understood from the following description and the accompanying drawings in which the same reference numerals designate the same or similar parts throughout the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a schematic view of the automatic apparatus for packaging powdered material with uniform bag weight and dust-free operation according to the invention;

FIG. 2 is a pictorial view illustrative of the operation of the pinch air exhaust device according to the invention;

FIG. 3 is a fragmentarily enlarged front view of the aerator units according to the invention;

FIG. 4 is a fragmentarily enlarged perspective view, partially broken away, of the housing in which an entrance of the feed pipe of the smaller diameter-for dribble flow is coated with a grid screen;

FIG. Sis a fragmentarily enlarged sectional view of the flow control system comprising the two feed pipes with pinch couplings of different diameters;

FIG. 6 is a pictorial view illustrative of the operation of the flow control means of FIG. 5 showing the larger coupling being squeezed shut, while the smaller coupling is being opened;

FIG. 7 is a fragrnentarily enlarged cross sectional view of the filling means according to the invention; FIG. 8 is a fragmentarily' enlarged cross sectional view of the filling means of another embodiment according to the invention which is provided at its base periphery with a retractable valve means for airtightly sealing the clearance to be formed between the filling means and the inlet of the bag;

FIG. 9 is a fragmentarily enlarged sectional view of the dust collecting means according to the invention; and

FIG. 10 is a pictorial view of the weighing means according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, the powdered material is charged into the serge bin I and subsequently the material in a suitable amount is dropped into the air chamber 3 by opening a cone valve 2.

At the inclined outer periphery of the air chamber is provided four aerator units 5 for fluidizing the powdered material in the air chamber 3. These four aerator units may be replaced by two or three units in order to achieve fluidization of the material to be packaged.

The compressed air supplied through an air pipe 6 is introduced into an intermediate chamber 7 and then blown into the air chamber 3 through an air-pervious pad 8 to fluidize the material in the air chamber. In this event, the powdered material is directed downwardly by the convection of the air into the housing 4 connected to the lower end of the air chamber 3.

A further aerator unit 9 is provided at the bottom of the housing 4 to receive the powdered material shifted from the air chamber 3 in fluidized state.

An air supply pipe 11 enters one side of the housing 4, through which a jet air is supplied into the housing so that vthe powdered material floating within .the housing by an action of the aerator 9 is urged into the feed pipe 17 of a smaller diameter for dribble flow of the material.

In the air chamber 3 as well as the housing 4 an air inflow through the pads 8 and 10 is continued even after the air charge exceeds the allowable limit, so that the powdered material is bound or bridged under the extensive air pressure increasing the air pressure more and more with increase of the coagulation of the material, and as the result the performance of the packer is remarkably reduced.

According to the invention, the exhaust pipes 12 and I3 are connected to the aerators 5 and 9 to relievethe pressure in the air chamber 3. The other ends of the exhaust pipes 12 are connected to an intermediate pipe 14 surrounding the aerator 5, which is further connected to a main conduit 15 communicating with the dust collecting means hereinafter illustrated.

The other end of the exhaust pipe 13 is connected to the intermediate pipe 14 communicating with the main conduit 15.

By this construction, excessive air permeates through the inclined air-pervious pads 8 and I0 stretched between the air chamber, the housing and the aerator units and is directed to the exhaust pipes 12 and 13 together with the dust and then collected into the dust chamber 33. Accordingly, the air-pervious pads do not prevent blocking the dust.

In FIG. 5, the flow control system comprises the feed pipe 16 of the larger diameter for the full flow of the material and the feed pipe 17 of smaller diameter for the dribble flow of the material which is provided with a detachable fitting 18 having a conical orifice. The inner diameter of the fitting 18 may be optionally and suitably determined in accordance with the particle size of the material to be packaged.

As is shown in FIG. 4, the entrance of the feed pipe I7 for the dribble flow is coated with a grid screen 19 to stop any inflow of the crude particles which are likely to clog the orifice of the feed pipe 17.

In case no such grid is provided in front of the entrance of the smaller feed pipe 17, a separate filtering means must be added to the packer in order to remove the crude particles, which increases relatively the cost of the apparatus.

The feed pipes 16 and 17 of different sizes are connected to a manifold 22 by the pinch couplings 20 and 21 and the manifold 22 is connected through a flexible tube 23 to a discharge spout 26.

The flow control system cooperates with the weighing system, and immediately before the powdered material packaged in the bag comes to the predetermined bag weight, the pinch coupling 20 of the larger diameter is squeezed shut by the cutoff device of known construction to close the feed pipe 16 for the full flow, while the pinch coupling 21 of the smaller diameter being opened to permit a dribble flow of the material as is shown in FIG. 6. When the material in the bag comes to the predetermined weight, the pinch coupling 21 of smaller diameter is squeezed shut to close the feed pipe 17 for dribble flow, so that the packaging operation is carried out under the uniform and accurate bag weight control.

In FIG. 7, the filling means 24 is secured to a flange 25 bearing a bag seat 40.

The filling means 24 comprises a discharge spout 26 and an outer sleeve 27. An open end of the outer sleeve 27 is provided with a mesh filter 28 such as the wire screen or cloth of mesh size corresponding to the particle size of the powdered material to be packaged. To the lower periphery of the outer sleeve 27 is connected an air exhaust conduit 29.

The powdered material discharged together with the air flow is precipitated in the bag 39, while the air is exhausted through the mesh filter 28 and the outer sleeve 27 to the exhaust conduit 29. In this case, some dust is exhausted together with the air flow, which is subsequently directed to the exhaust conduit 29 and collected in the dust chamber 33, so that any leakage of the dust from the apparatus may be prevented.

According to this construction, an automatic packaging of the powdered material into the air impervious bag may be effected with a higher speed as compared with the conventional packer. In the outer sleeve is arranged an air cleanout pipe 30 for cleaning the mesh filter 28 to prevent any clogging thereof.

In FIG. 8, the outer sleeve 27 at its outer periphery is provided with a retractable valve 31 to which an air supply pipe 32 is connected. After the insertion of the filling means 24 into the inlet of bag 39, the air is supplied into the retractable valve 31 to expand the same spherically as is shown in FIG. 8 so that the clearance formed between the inlet of the bag 39 and the filling spout 24 is sealed airtightly to inhibit any leakage of the material. The air supply pipe 32 is reversible and after the packaging operation is finished, the air in the valve 31 is exhausted through the air supply pipe 32 to retract the valve 31 to the original flat state.

The dust collecting means comprises a drum chamber 33 having a conical lower portion, with which the main conduit 15 leading from the aerator units 5 and 9 and the exhaust conduit 29 from the filling means 24 are communicated as is shown in FIG. 9. An air supply pipe 34 enters the chamber 33 to urge the dust fed by the main conduit 15 and the exhaust conduit 29.

The dust chamber 33 at its lower portion is connected to a feed back conduit 35 and the other end thereof is communicated with the serge bin 1. Accordingly, the dust collected in the chamber 33 is fed back to the serge bin 1 without leakage and charge again into the air chamber 3.

The air pooled in the serge bin 1 is discharged to the atmosphere through an air vent 39 provided with a filter means and after the packaging operation the air in the air chamber is exhausted through the exhaust pipe 37 and fed to the serge bin 1.

As is shown in FIG. 2, the exhaust pipe 37 is provided with an auxiliary cleanout pipe 38, so that when a flexible coupling 37a is squeezed shut by the cutoff device of known construction, a pinch coupling 38a is opened to supply the air through the cleanout pipe 38 whereby to clean the inside of the exhaust pipe 37. On the other hand, when the coupling 37a is opened to exhaust the .air in the air chamber, the pinch coupling 38a is squeezed by means of the cutoff device such as the air cylinder.

A bag seat 40 is surmounted with the bag 39 for containing the powdered material and when the powdered material in the bag comes to the predetermined bag weight, the weighing means cooperates with the flow control system to ensure the packaging with uniform and accurate bag weight.

The weighing means comprises the bag seat, balance weighing mechanism and detecting means FIGS. 1 and 10), and the seat 40 is shifted downwardly in proportion to an increase of the filling of powdered material material into the bag 39. In this case, the filling means 24 is bent downwardly in accordance with the downward movement of the weighing seat 40 since the weighing seat 40 and the filling means 24 are integrally secured to the flange 25.

The downward movement of the weighing seat 40 is transferred through the flange 25, a main lever 41, a draft rod 42, an extension lever 43 and a draft rod 44 to a scale beam 45 of the balance weighting system (A) to raise the right-hand end of the said scale beam 45. The left-hand end of the scale beam is provided with a center weight 46 to inhibit any oscillation of the scale beam.

The scale beam 45 at its right-hand side is provided with an exchangeable main weight means 48, which is somewhat below the predetermined bag weight, through a suspension rod 47 which is provided at its lower end with a collar support 50 for bearing an auxiliary weight means 49 which satisfies the final bag weight.

In advance with the packaging operation, the right terminal of the scale beam 45 is somewhat raised resisting the main weight means 48, so that a slit plate 51 fitted to the scale beam 45 actuates a primary photoelectric detector 52 which cooperates with the flow control system to pinch the coupling 20 of the feed pipe 16 for full flow of the material. While during the operation of the primary photoelectric detector 52, the collar support 50 is raised to the level for receiving the bottom of the auxiliary weight means 49 lying on the floor flame 54 whereby to exert an additional weight on the scale beam 45. Whereafter, the powdered material is fed only through the small feed pipe 17 for dribble flow and when the filling of powdered material comes to the predetermined bag weight, the scale beam 45 is tilted to enable slit plate 51 to actuate a secondary photoelectric detector 53 which cooperates with the flow control system to shut the small feed pipe 17 whereby to finalize the packaging operation.

In the weighing mechanism mentioned above, the operation of the primary photoelectric detector 52 induces the starting of the timer of the delay open relay circuit to energize a solenoid 55 which makes a magnetic contact with one end of an auxiliary beam 56 to fix the auxiliary weight means 49 on the floor 54 so that any unnecessary suspension of the auxiliary suspension rod 47 is positively suption with a highly uniform-bag weight with the maximum weighing error of 1/5000 which is an amazing value-as compared with those obtainable by the conventional packaging apparatus'of this class. i

Further, according to the invention, a perfect dust-free operation may be achieved'since the dust is completely collected by the circulation system.

it will be appreciated that in lieu of the aerator units arranged at the conical lower portion of the air chamber, a vertical screw conveyor can be disposed along the center axis of the air chamber to convey the wet powdered materials such as salt, sugar and the like into the housing, while satisfactorily stirring such wet powdered material.

While certain preferred embodiments of the invention have been illustrated by way of example in the drawings and particularly described, it will be understood that various modifications may be made in the apparatuses and constructions and that the invention is no way limited to the embodiments shown. 4

I claim:

1. An automatic packaging apparatus for powdered material, said apparatus comprising a hopper for containing such material, a chamber disposed beneath said hopper, said chamber being provided in its upper portion with an air exhaust outlet for discharging air therefrom after packaging has been finished and at its lower portion with air inlet means for blowing air into said chamber to fluidize said material moving therethrough, a housing arranged beneath the bottom of said chamber, said housing being provided with a second air inlet means for admitting air' into said housing for fluidizing the material delivered thereto, said housing being provided at a point above said second air inlet means with an air supply pipe I for urging the fluidized material through and out of said housing, feed pipe means connected to and communicating with said housing for'receiving material moved by said air supply pipe, flow control means connected to said-feed pipe means for controlling the rate of flow of the material through said feed pipe means, filling means associated with said flow control means for discharging the material into a bag, automatic weighing means operatively connected to said flow control means to selectively regulate material flow according to bag weight whereby a plurality of bags may be filled to a uniform weight, and means for feeding dustin said chamber and at said filling means back into said hopper for recirculation of said dust.

2. Apparatus according to claim 1 wherein each of said air inlets comprises a casing which is provided at one side with an air pervious pad and at the other side with an air supply pipe of large diameterand an air exhaust pipe of small diameter for relieving air pressure both in the chamber and in the housing.

3. Apparatus according to claim 1 wherein said air exhaust outlet comprises an air exhaust pipe'of large diameter and a cleanout pipe of small diameter, which are connected to two flexible coupling pipes of difi'erent diameters which can be pinched alternately by a flow cutoff arrangement.

4. Apparatus according to claim 1 wherein said flow control means comprises a control pipe of large diameter for full flow of the material to be packaged and a control pipe-of small diameter for dribble flow of the material, both of said control pipesbeing connected to a manifold by two flexible coupling control pipes of different diameters which can be pinched alternately by a flow cutoff control arran ement.

5. Apparatus according to claim 4 w erein the entrance to said control feed pipe for dribble flow is provided with a grid screen for preventing passage of large particles of the material through said control feed pipe.

6. Apparatus according to claim 1 wherein said filling means comprises a discharge spout connected to said flow control means by a flexible coupling, for discharging the material into a bag, an outer sleeve surrounding said discharge spout for providing an air exhaust path, the end of said outer sleeve being provided with a filtering mesh for releasing air from the bag while preventing escape of the material therefrom, and an air cleanout pipe in the outer sleeve for cleaning said filtering mesh.

7. Apparatus according to claim 6 wherein said outer sleeve is provided around a portion of its outer periphery with an expansible membrane whose interior communicates with an air supply pipe for sealing the inlet of the bag airtightly during filling of the bag. e

8. Apparatus according to claim 1 wherein said automatic weighing means comprises a seat for a bag, a weighing mechanism including a main balancing 'weight somewhat lighter than a predetermined desired filled bag weight and an auxiliary weight for balancing the predetermined bag weight, detecting means operative just before the predetermined bag weight is attained, and means for temporarily stopping the auxiliary weight at a certain level.

9. Apparatus according to claim 1 wherein said dust feeding means has an upper cylindrical portion, to which dust conduit means for each air inlet and from thefilling means are connected and a conical lower portion to which an air supply pipe is connected, an opening in the lower end of said lower portion being connected to a feed back conduit loading to said hopper. 

2. Apparatus according to claim 1 wherein each of said air inlets comprises a casing which is provided at one side with an air pervious pad and at the other side with an air supply pipe of large diameter and an air exhaust pipe of small diameter for relieving air pressure both in the chamber and in the housing.
 3. Apparatus according to claim 1 wherein said air exhaust outlet comprises an air exhaust pipe of large diameter and a cleanout pipe of small diameter, which are connected to two flexible coupling pipes of different diameters which can be pinched alternately by a flow cutoff arrangement.
 4. Apparatus according to claim 1 wherein said flow control means comprises a control pipe of large diameter for full flow of the material to be packaged and a control pipe of small diameter for dribble flow of the material, both of said control pipes being connected to a manifold by two flexible coupling control pipes of different diameters which can be pinched alternately by a flow cutoff control arrangement.
 5. Apparatus according to claim 4 wherein the entrance to said control feed pipe for dribble flow is provided with a grid screen for preventing passage of large particles of the material through said control feed pipe.
 6. Apparatus according to claim 1 wherein said filling means comprises a discharge spout connected to said flow control means by a flexible coupling, for discharging the material into a bag, an outer sleeve surrounding said discharge spout for providing an air exhaust path, the end of said outer sleeve being provided with a filtering mesh for releasing air from the bag while preventing escape of the material therefrom, and an air cleanout pipe in the outer sleeve for cleaning said filtering mesh.
 7. Apparatus according to claim 6 wherein said outer sleeve is provided around a portion of its outer periphery with an expansible membrane whose interior communicates with an air supply pipe for sealing the inlet of the bag airtightly during filling of the bag.
 8. Apparatus according to claim 1 wherein said automatic weighing means comprises a seat for a bag, a weighing mechanism including a main balancing weight somewhat lighter than a predetermined desired filled bag weight and an auxiliary weight for balancing the predetermined bag weight, detecting means operative just before the predetermined bag weight is attained, and means for temporarily stopping the auxiliary weight at a certain level.
 9. Apparatus according to claim 1 wherein said dust feeding means has an upper cylindrical portion, to which dust conduit means for each air inlet and from the filling means are connected and a conical lower portion to which an air supply pipe is connected, an opening in the lower end of said lower portion being connected to a feed back conduit loading to said hopper. 